This invention concerns the use of 2-phenoxyethanol as a bacteriostatic and fungistatic agent and sodium fluoride as a stabilization agent in reagents utilized in hematological studies utilizing electronic particle analysis apparatus of the COULTER type.
In the referenced copending application, there was disclosed a multipurpose, electrolytic solution for use in hematological procedures principally, enumeration of blood cells and the determination of hemoglobin concentration and other important parameters of a blood sample by means of automated electronic particle analysis apparatus of the COULTER type. The solution was balanced osmotically for mean cell volume stability, was azide-free and utilized 2-phenoxyethanol as a bacteriostatic and fungistatic agent.
Sodium fluoride was employed to counterbalance the cell wall weakening activity of 2-phenoxyethanol and thus stabilize the mean cell volume of the red cells. Also, sodium fluoride served to aid in the conversion of hemoglobin to cyanmethemoglobin for the determination of hemoglobin colorimetrically.
The use of a bacteriostatic and fungistatic agent brings about heretofore undesirable variations in the mean cell volume of the red cells leading to the unstabilization of the mean red cell volume. In the desirability of utilizing a bacteriostatic agent as a replacement for sodium azide, as explained in my copending application, 2-phenoxyethanol was selected although it had never been employed heretofore in such capacity. However, the 2-phenoxyethanol may lead to the destruction of the cell walls or change of cell volume. In order to avoid the problems of hemolysis or crenation, a stabilizer was utilized in the resulting system. Although sodium fluoride had long been known to be a preservative, such as for preserving glucose in blood samples, its utility as a stabilizer with the resulting system was unexpected.